The study is designed to select a dose of GSK1265744 primarily on the basis of antiviral activity and tolerability in HIV-1 infected, antiretroviral naive subjects.

This study consists of two parts:

Induction Phase: Approximately 200 subjects will be randomized (50 subjects in each of the 4 treatment arms). The Induction Phase consists of a 24 week dose-ranging evaluation of GSK1265744 at blinded doses of 10 mg, 30 mg and 60 mg once-daily and a control arm of open-label efavirenz (EFV) 600 mg once daily. The background dual nucleoside reverse transcriptase inhibitor (NRTI) antiretroviral therapy (ART) for all arms will be either abacavir/lamivudine (ABC/3TC) or tenofovir/emtricitabine (TDF/FTC) as selected by the Investigator. Subjects randomized to a GSK1265744 containing arm, who successfully complete 24 weeks on study and demonstrate virologic suppression (defined as having a plasma HIV-1 ribonucleic acid [RNA] <50 copies per milliliter [c/mL] before Week 24, with no signs of virologic rebound) will become eligible for the Maintenance Phase of this study.

Maintenance Phase: The background NRTIs will be discontinued and the subjects will continue their randomized dose of GSK1265744 in combination with rilpivirine (RPV) 25 mg once-daily for an additional 72 weeks. The Maintenance phase will evaluate the ability of this two drug ART regimen to maintain virologic suppression through Week 48, Week 72 and Week 96. Subjects randomized to the EFV arm will continue on their randomized regimen through Week 96.

After completion of the maintenance phase, subjects could enroll in the Open-Label Phase to continue GSK1265744 + RPV treatment as long as they continue to derive clinical benefit and until it is locally approved and commercially available.

Proportion of subjects with HIV-1 RNA <50 copies/mL at Week 48 will be based on Intent-to-Treat Exposed (ITT-E) Population (all randomized subjects who received at least one dose of study drug) using the missing, switch, or discontinuation equals failure (MSDF) algorithm.

Secondary Outcome Measures:

Proportion of subjects with plasma HIV-1 RNA <400 and <50 copies/mL over time by visit [ Time Frame: Through Week 96 ] [ Designated as safety issue: No ]

Proportion of subjects with plasma HIV-1 RNA <400 and <50 copies/mL over time by visit will be calculated using the MSDF and observed algorithm.

Proportion of subjects with HIV-1 RNA <50 copies/mL at Week 16 and Week 24 in Induction Phase will be based on ITT-E Population and MSDF algorithm.

The proportion of subjects with HIV-1 RNA <50 copies/mL from Week 24 through Week 96 by visit in Maintenance Phase [ Time Frame: 24 weeks through Week 96 ] [ Designated as safety issue: No ]

The proportion of subjects with HIV-1 RNA <50 copies/mL from Week 24 through Week 96 will be determined by visit for the ITT-ME Population (all randomized subjects who received at least one dose of investigational product [IP] during the Maintenance Phase of the study) using MSDF algorithm.

Absolute values and change from Baseline in plasma HIV-1 RNA by visit [ Time Frame: Baseline (Study Day 1), and up to Week 96 ] [ Designated as safety issue: No ]

Plasma for quantitative HIV-1 RNA will be collected at every visit from baseline till Follow-up. Methods to determine absolute plasma HIV-1 RNA may include but are not limited to the Abbott RealTime HIV-1 Assay lower limit of detection (LLOD) 40 c/mL. Change from Baseline will be calculated as post-Baseline value minus the Baseline value.

Incidence of disease progression [ Time Frame: Up to Week 96 ] [ Designated as safety issue: No ]

Disease progression includes HIV-associated conditions, acquired immunodeficiency syndrome (AIDS) and death. HIV-associated conditions will be assessed according to the 1993 Centers for disease control and prevention (CDC) Revised Classification System for HIV Infection in Adults.

Absolute values and changes from baseline in CD4+ cell counts by visit [ Time Frame: Baseline (Study Day 1), and up to Week 96 ] [ Designated as safety issue: No ]

Lymphocyte subsets (including CD4+) will be collected for assessment by flow cytometry.

Incidence of treatment emergent genotypic and phenotypic resistance to GSK1265744, RPV and other on-study ART for protocol-defined virologic failures [ Time Frame: Up to Week 96 ] [ Designated as safety issue: No ]

Development of viral resistance to GSK1265744 and other on-study ART in subjects experiencing virologic failure through Week 24, and viral resistance to GSK1265744 and rilpivirine in subjects experiencing virologic failure from Week 24 through Week 96 will be evaluated. Genotypic and phenotypic analyses may be carried out using, but not limited to, Standard Phenosense and GenoSure testing methods for protease (PRO) and reverse transcriptase (RT), or with GeneSeq Integrase and PhenoSense Integrase assays.

Incidence and severity of Adverse Events (AEs) and laboratory abnormalities over time [ Time Frame: Up to Week 96 ] [ Designated as safety issue: No ]

The incidence and severity of AEs and laboratory abnormalities will be determined throughout the study for the Safety Population (all randomized subjects who will be exposed to IP). AEs should be graded according to the Division of AIDS (DAIDS) toxicity scales. AEs and laboratory abnormalities will also be summarized separately for Induction Phase, and Maintenance Phase using the Maintenance Safety Population (all randomized subjects who will be exposed to IP during the Maintenance Phase of the study).

Absolute values and changes in laboratory parameters by visit [ Time Frame: Up to Week 96 ] [ Designated as safety issue: No ]

Monitoring of hematology, blood chemistry and fasting lipids will be done, and changes by visit will be summarized.

Proportion of subjects who discontinue treatment due to AEs [ Time Frame: Up to Week 96 ] [ Designated as safety issue: No ]

Proportion of subjects who discontinue treatment due to AEs will be determined throughout the study for the Safety Population; subjects who discontinue treatment due to AEs through Week 24 will be also determined in the Induction Phase; and subjects who discontinue treatment due to AEs from Week 24 through Week 96, will be determined using the Maintenance Safety Population.

Incidence of any clinically significant changes in QRS duration, QTc interval, HR, PR interval based on electrocardiograph (ECG) readings by visit [ Time Frame: Baseline (Study Day 1), and up to Week 96 ] [ Designated as safety issue: No ]

ECGs will be performed in triplicate at least 5 minutes apart and following 5 minutes of rest in a semi-supine position within 1 hour prior to first dose. Subsequent ECG evaluations during the study should be obtained 2 to 4 hours after GSK1265744 dose.

The Plasma GSK1265744 PK parameters will be estimated by non-compartmental analysis and/or population PK. The PK data collected in this study will be included in the analysis to investigate the exposure-response relationship and the integrated drug-viral dynamic modeling which will ultimately be used in guiding dose selection.

GSK1265744 10 mg will be administered orally once daily in combination with investigator-selected background NRTIs in the Induction Phase of the study and in combination with Rilpivirine 25 mg in the Maintenance Phase of the study.

Drug: Rilpivirine 25 mg

Rilpivirine 25 mg will be administered orally once daily in combination with GSK1265744 10 mg, 30 mg and 60 mg in the Maintenance Phase of the study.

Drug: Placebo

Placebo matching to GSK1265744 will be administered along with GSK1265744 10 mg and 30 mg in the Induction phase and Maintenance phase of the study.

The background dual NRTI therapy for all arms in the Induction Phase and Efavirenz 600 mg arm in the Maintenance Phase will be either abacavir 600 mg + lamivudine 300 mg (ABC/3TC) or tenofovir 300 mg + emtricitabine 200 mg (TDF/FTC) as selected by the Investigator.

GSK1265744 30 mg will be administered orally once daily in combination with investigator-selected background NRTIs in the Induction Phase of the study and in combination with Rilpivirine 25 mg in the Maintenance Phase of the study.

Drug: Rilpivirine 25 mg

Rilpivirine 25 mg will be administered orally once daily in combination with GSK1265744 10 mg, 30 mg and 60 mg in the Maintenance Phase of the study.

Drug: Placebo

Placebo matching to GSK1265744 will be administered along with GSK1265744 10 mg and 30 mg in the Induction phase and Maintenance phase of the study.

The background dual NRTI therapy for all arms in the Induction Phase and Efavirenz 600 mg arm in the Maintenance Phase will be either abacavir 600 mg + lamivudine 300 mg (ABC/3TC) or tenofovir 300 mg + emtricitabine 200 mg (TDF/FTC) as selected by the Investigator.

GSK1265744 60 mg will be administered orally once daily in combination with investigator-selected background NRTIs in the Induction Phase of the study and in combination with Rilpivirine 25 mg in the Maintenance Phase of the study.

Drug: Rilpivirine 25 mg

Rilpivirine 25 mg will be administered orally once daily in combination with GSK1265744 10 mg, 30 mg and 60 mg in the Maintenance Phase of the study.

The background dual NRTI therapy for all arms in the Induction Phase and Efavirenz 600 mg arm in the Maintenance Phase will be either abacavir 600 mg + lamivudine 300 mg (ABC/3TC) or tenofovir 300 mg + emtricitabine 200 mg (TDF/FTC) as selected by the Investigator.

The background dual NRTI therapy for all arms in the Induction Phase and Efavirenz 600 mg arm in the Maintenance Phase will be either abacavir 600 mg + lamivudine 300 mg (ABC/3TC) or tenofovir 300 mg + emtricitabine 200 mg (TDF/FTC) as selected by the Investigator.

Eligibility

Ages Eligible for Study:

18 Years and older

Genders Eligible for Study:

Both

Accepts Healthy Volunteers:

No

Criteria

Inclusion Criteria:

HIV-1 infected male or female subjects >= 18 years of age

Screening plasma HIV-1 RNA >=1000 c/mL

CD4+ cell count >=200 cells/millimeter (mm)^3

ART-naive defined as having =<10 days of prior therapy with any antiretroviral agent following a diagnosis of HIV-1 infection

Female subjects of child bearing potential are eligible to enter if they are not pregnant and willing to use protocol-specified methods of contraception to prevent pregnancy during the study

Exclusion Criteria:

Any evidence at screening of an active Centers for Disease and Prevention Control (CDC) Category C disease

Treatment with an HIV-1 immunotherapeutic vaccine within 90 days of Screening

History of ongoing or clinically relevant hepatitis within the previous 6 months, and subjects with moderate to severe hepatic impairment will be excluded

Women who are breastfeeding

Subject, who in the investigator's judgment, poses a significant suicide risk

Any clinically significant finding on screening or baseline electrocardiograph (ECG)

The presence of any specific laboratory abnormalities at Screening

History of cardiac disease

Clinically relevant pancreatitis

Subjects who are unlikely to complete the dosing schedule due to a pre-existing physical or mental condition

Any condition which impairs the absorption, distribution, metabolism or excretion of the investigational product

Any evidence of primary resistance based upon the presence of a major resistance associated mutation in the Screening HIV genotype, or any historical genotype

Treatment with any protocol-specified excluded medication

Contacts and Locations

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study.
To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below.
For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01641809